Hepatology: Acute Liver Failure

Question 1

Define acute liver failure [1]

Answer 1

Acute liver failure (ALF) is a rapid decline in hepatic function characterised by jaundice, coagulopathy (INR >1.5), and hepatic encephalopathy in patients with no evidence of prior liver disease

Question 2

State causes of acute liver failure [4]

Answer 2

• Drugs: paracetamol; alcohol
• Infection: Hep A / B / E
• Poor Nutrition
• Pregnancy

Question 3

Describe the clinical features of someone suffering from acute liver failure [5]

Answer 3

• Jaundice
• coagulopathy: raised prothrombin time: INR >1.5
• Hypoalbuminaemia
• Hepatic encephalopathy
• Renal failure is common (‘hepatorenal syndrome’)

Question 4

Describe which investigations are required if suspect acute liver failure? [8]

Answer 4

LFTs:
- hyperbilirubinaemia (associated with jaundice - defining feature of ALF)
- elevated liver enzymes: raised AST / ALTs

Prothrombin time:
- INR > 1.5

Elevated urea & creatinine (due to associated renal damage)

FBC:
- leukocytosis (due to infection)
- thrombocytopenia
- anaemia

ABG:
- metabolic acidosis (esp. if paracetamol OD)

Arterial blood lactate:
- Important prognostic indicator in paracetamol-associated ALF

Pregnancy test

Viral & autoimmune hepatitis markers

Question 5

What specific investigations would reveal that Ptx is suffering from paracetamol OD? [4]

Answer 5

• Raised AST or ALTs (5x above normal levels)
• ALP (2x above normal)
• Metabolic acidosis: due to raised lactate levels

Question 6

State 5 risk factors for ALF [5]

Answer 6

• Chronic alcohol misuse
• Poor nutrional status: increased risk of paracetamol toxicity if fasting
• Female sex
• Pregnancy
• Chronic Hep B
• Chronic Pain / Narcotic use

Question 7

What ABG result would indicate paracetamol overdose? [1]

Answer 7

metabolic acidosis

Question 8

[] therapy should be given in all cases of paracetamol overdose regardless of the dose or timing of paracetamol ingestion.

Answer 8

N-Acetylcysteine (NAC) therapy should be given in all cases of paracetamol overdose regardless of the dose or timing of paracetamol ingestion

Question 9

How do you manage Ptx with ALF? [6]

Answer 9

• Monitor for encephalopathy and conscious state.
• Administer N-acetylcysteine in all patients with acute liver failure, regardless of aetiology
• Insert a urinary catheter and monitor urine output hourly
• Blood glucose should be monitored by nursing staff every 2 hours for hypoglycaemia.
• Baseline tests depend on the history ie paracetamol levels following an overdose
• Arrange USS abdomen with Doppler of hepatic veins

Question 10

Across Europe, [] is the most common cause of ALF.

Answer 10

drug-induced liver injury:
- may be divided into paracetamol or non-paracetamol DILI.

Question 11

Which viruses are most likely to cause ALF?[3]

Answer 11

Hep A, B, E

Question 12

Name three non-paracetamol medications can cause ALF [3]

Answer 12

Non-paracetamol medications: Statins, Carbamazepine, Ecstasy

Question 13

What is Budd-chiari syndrome? [1]

Answer 13

Budd-Chiari syndrome is a vascular liver disorder due to obstruction of hepatic venous outflow:

Describes a condition characterised by occlusion or partial occlusion of any, or all, the three major hepatic veins. This may occur with or without occlusion of the IVC.

Question 14

How can ALF lead to death? [5]

Answer 14

Most cases of ALF are associated with a direct insult to the liver leading to massive hepatocyte necrosis

As the condition progresses it can lead to a hyperdynamic circulatory state with low systemic vascular resistance due to a profound inflammatory response

This causes poor peripheral perfusion and multi-organ failure

Patients also develop significant metabolic derangements (e.g. hypoglycaemia, electrolyte derangement) and are at increased risk of infection.

Marked cerebral oedema occurs, which is a major cause of morbidity and mortality in ALF.